Bringing SANs to the Masses

While SANs have proven value for large data center applications, until recently it has been unclear whether SAN technology could provide comparable value for medium-sized and smaller businesses. Tom Clark reveals how recent market developments such as lower cost modular shared storage arrays, more economical disk drives, and IP-based storage products are generating a lower entry cost for SANs and are bringing shared storage to a broader market.

Vendors sell technology that hopefully fulfills a customer's application requirements. Unfortunately, vendors usually know far more about the "speeds and feeds" of their particular products than they do about real customer needs. And although customers are very close to their own specific business agendas, they may not be able to effectively align those business requirements to the plethora of IT product offerings in the market.

As a consequence, customers are sometimes sold solutions that do not fully address their problems, or they postpone making acquisitions despite the existence of viable but under-marketed solutions. Storage area networks, for example, offer many customer benefits, including reduced storage administration overhead and higher availability of data, but not all customers or departments within larger enterprises can realistically justify the investment in a SAN solution. As always, the key to matching a solution to a problem is a firm understanding of what the problem actually is.

SANs have made inroads primarily within the top tier enterprise networks. In these environments, the storage problems customers face are fairly obvious. The reactive and spontaneous acquisition of direct-attached storage and servers results in unwieldy and expensive storage administrative costs, under-utilized capacity, and bloated IT budgets that never quite catch up with growing data storage needs. Some large enterprises have thousands of servers and thousands of direct-attached storage arrays to manage, which not only requires a large staff of server and storage administrators, but frequently results in duplication of applications and files, and makes upgrading operating systems and applications untenable as well. Implementing SAN technology, on the other hand, provides a ready means for dramatically reducing the number of storage arrays and administrators, streamlining OS and application management, reducing the number of servers, and, as a side benefit, facilitating high availability of data via SAN-based data replication and server clustering.

Although SANs have proven end-user value for large data center applications, it may be unclear whether SAN technology can provide comparable value for typical departmental or medium-sized and smaller businesses. A department with a few servers and storage arrays may see more efficient utilization of storage and simplified tape backup by deploying a SAN, but the return on investment may not offset the higher acquisition cost associated with conventional SANs. In this case, the customer may have upgraded its storage infrastructure and made the lives of its storage administrators somewhat easier, but at no real savings in day to day operations.

Shared Storage for a Broader Market

For the productive application of SANs in medium and small businesses, the acquisition cost of a SAN solution must be significantly lower than that of conventional Fibre Channel SANs and not appreciably higher than the cost of direct-attached storage alternatives. This need is being addressed by storage platform providers in the form of lower cost modular shared storage arrays, more economical disk drives, and new IP-based storage products. In combination, these new technologies offer a lower entry cost for SANs and bring shared storage to a broader market.

Modular shared storage is designed to provide a lower threshold for implementing a storage network. Instead of buying a larger, more expensive chassis that can be filled with disks as needed, the customer can buy a compact chassis that can be integrated with other modular units over time. This pay as you grow option is bringing enterprise-class shared storage into the sub-hundred thousand dollar range while still providing many of the advanced RAID and high availability features common to higher end products.

The cost reduction offered by modular storage is augmented by lower priced disk drives with new serial-attached SCSI (SAS) or Serial ATA (SATA) interfaces. Disk drive technology for previously less reliable drives has improved significantly, making it feasible to commit mission-critical business data to commodity media. Although this technology maturation is cutting into the already thin margins of disk manufacturers, it is accelerating the development of high capacity, fast, reliable, and cheap storage solutions. Customers with relatively modest requirements and limited budgets can now consider the more economical shared storage options available in the market and circumvent the inevitable overhead that results from the continued accumulation of direct-attached storage.